The Adams County district on Friday announced that the start of classes was being moved up three weeks as a result of a mold concern in all buildings.

The first day of school, which had previously been set for Aug. 21, will now be Sept. 4.

"I apologize for the short notice, but we have recently confirmed the need to delay the start of the school year in order to allow the district to bring professionals to clean all buildings and ventilation systems prior to accepting staff and students," said district Superintendent Karen Kugler.

Symptoms of mold allergies include runny nose, post-nasal drip, coughing and wheezing. In some cases, mold can cause more serious problems, such as strong allergic reactions in the lungs or sinuses and hypersensitivity pneumonitis -- an inflammation of the lungs.

Other health problems associated with mold include toxic mold syndrome and sick building syndrome.